Ethology is the study of animal behavior. Behavior is an
animal's response to sensory input, and falls into two basic
categories: learned and innate (inherited).

Orientation behaviors place the animal in its most
favorable environment. In taxis, the animal moves toward or
away from a stimulus. Taxis is often exhibited when the stimulus is
light, heat, moisture, sound,or chemicals. Kinesis is a
movement that is random and does not result in orientation with
respect to a stimulus. If an organism responds to bright light by
moving away, that is a taxis. If an animal responds to bright light
by random movements in all directions, that is kinesis.

Agonistic behavior is exhibited when animals respond to
each other by aggressive or submissive responses. Often the agonistic
behavior is simply a display that makes the organism look big or
threatening. It is sometimes studied in the laboratory with Bettas
(Siamese Fighting Fish).

Mating behaviors may involve a complex series of activities
that facilitate finding, courting, and mating with a member of the
same species.

Exercise 11A: General Observation of Behaviors

In this lab, you will be working with terrestrial isopods commonly
known as pillbugs, sowbugs, or roly-polies. These organisms are
members of the Phylum Arthropoda, Class Crustacea, which also
includes shrimp and crabs. Most members of this group respire through
gills.

Procedure

1. Place 10 pillbugs and a small amount of bedding material in a
small petri dish. They generally try to get out so cover the dish
with plastic wrap or a petri dish cover.

2. Observe the pillbugs for 10 minutes. Make notes on their
general appearance, movements about the dish, and interactions with
each other. Notice if they seem to prefer one area over another, if
they keep moving, settle down or move sporadically. Note any
behaviors that involve 2 or more pillbugs. Do not interfere with the
specimens in any way.

1. Prepare a choice chamber. The choice chamber consists of two
large plastic petri dishes taped together with an opening cut in
between. Several alternatives to this concept can be produced. Take 2
plastic petri dishes and cut out 1 , 1/2 inch openings at the side.
Place the petri dishes together, matching the cut ends. Now tape the
petri dishes together by placing a strip of tape under each one. The
dishes now can be used to test for the variables.

2. Choose your variables to be tested: Moisture, light, and set up
the adjacent room accordingly. Use a soft brush to transfer ten
pillbugs from the stock culture into the center choice chamber. Cover
all chambers being used.

3. Count how many pillbugs are on each side of the choice chamber
every 30 seconds for 10 minutes. Record your data in Table 11.1.
Continue to record even if they all move to one side or stop
moving.

4. Return your pillbugs to the stock chamber.

5. Graph both the number of pillbugs in the wet chamber and the
number in the dry chamber using the graph below.

Table 11.1

Time (Mins)

Number in Wet Chamber

Number in Dry Chamber

nnnnOther
Notesnnn

0

y

y

yyyyyyyyyyyyyyyyyyy

0.5

f

f

f

1.0

f

f

f

1.5

f

f

f

2.0

d

d

d

2.5

d

d

d

3.0

d

d

d

3.5

d

d

d

4.0

d

d

d

4.5

d

d

d

5.0

d

d

d

5.5

d

d

d

6.0

d

c

c

6.5

d

c

c

7.0

d

c

c

7.5

d

c

c

8.0

d

c

c

8.5

d

c

c

9.0

d

c

c

9.5

d

c

c

10.0

d

c

c

Graph Title
_____________________________________________

Graph 11.1

Analysis

1. What conclusions do you draw from your data? Explain
physiological reasons for the behavior observed in this activity.